Latch and v band coupler

ABSTRACT

A &#39;&#39;&#39;&#39;V&#39;&#39;&#39;&#39; band coupler having arcuate segments pivoted to a bottom hinge with a latch mechanism connecting the upper segment ends. The latch mechanism comprises two sections each having a web and a pair of flanges pivoted to the upper ends of the coupler segments. The head of a bolt is pivoted to one latch section and extends through the web of the other, a nut on the bolt drawing the latch sections together when tightened. Bridges on the latch sections initially engage the segments so as to create angular closing forces thereon. However, the latch sections have facing edges which contact above the bolt centerline, changing the pulling angle on the segments until it is parallel to the bolt axis. Any overtorque is taken up in the latch, protecting the segments.

United States Patent [191 Nixon [4 1 Mar. 19, 1974 LATCH AND V BANDCOUPLER [75] Inventor: Larry R. Nixon, Michigan Center,

[21] Appl. No.: 287,765

[52] U.S. CI 24/285, 285/411, 285/420 [51] Int. Cl B65d 63/02 [58] Fieldof Search 24/279, 285, 284, 280, 24/263 DL; 285/367, 410, 411, 420

[5 6] References Cited UNITED STATES PATENTS 3,661,409 5/1972 Brown eta1. 24/285 FOREIGN PATENTS OR APPLICATIONS 663,646 12/1951 Great Britain285/420 638,761 6/1950 Great Britain 285/411 553,141 2/1958 Canada285/410 1,104,922 3/1968 Great Britain 24/279 Primary Examiner-BernardA. Gelak Assistant Examiner-Kenneth Borner Attorney, Agent, orFirm-l-larness, Dickey & Pierce 5 7 ABSTRACT A V band coupler havingarcuate segments pivoted to a bottom hinge with a latch mechanismconnecting the upper segment ends. The latch mechanism comprises twosections each having a web and a pair of flanges pivoted to the upperends of the coupler segments. The head of a bolt is pivoted to one latchsection and extends through the web of the other, a nut on the boltdrawing the latch sections together when tightened. Bridges on the latchsections initially engage the segments so as to create angular closingforces thereon. However, the latch sections have facing edges whichcontact above the bolt centerline, changing the pulling angle on thesegments until it is parallel to the bolt axis. Any overtorque is takenup in the latch, protecting the segments.

7 Claims, 5 Drawing Figures LATCH AND V BAND COUPLER BACKGROUND OF THEINVENTION The invention relates to latch mechanisms which may be usedwith couplers of the V" band type having arcuate segments connected attheir lower ends by a hinge and capable of drawing together ducts orother members having abutting flared flanges. A problem which existswith present day constructions of this general type is that the forcesare exerted by the latch mechanism on the coupling segments indirections of lesser segment strength. This may cause failure of thesesegments upon overtorquing of the latch mechanism. Conventional latchmechanisms for such couplers are also quite expensive to manufacture.

BRIEF SUMMARY OF THE INVENTION It is an object of the present inventionto provide a novel and improved latch mechanism for a segmented couplerwhich allows large installation torques to be applied withoutoverstressing these segments.

It is another object to provide a novel and improved latch mechanism ofthis nature which can be constructed to carry a predetermined capacityat substantially lower cost than conventional latch mechanisms of thisgeneral type.

It is another object to provide an improved latch and coupler mechanismwhich allows a non-catastrophic failure mode in that during and afterfailure of the coupler maintains a semi-closed position, preventingcomplete separation of the ducting or other clamped parts.

Briefly, the illustrated embodiment of the invention comprises a couplerhaving facing arcuate segments pivoted to a hinge at the bottom, and alatch mechanism for drawing together the tops of said segments. Thelatch mechanism comprises two latch sections pivoted to said segments, abolt having a head pivoted to one section and passing through the othersection, a nut on said bolt, means responsive to rotation of said nutfor drawing together said segments, bridges on said latch sectionsengageable with tops of said segments during initial tightening of thenut to create a combined rotational and direct pulling force on thesegments, and facing edges on the segments so shaped that continuedtightening of the nut will cause the edges to contact each other abovethe bolt axis, whereby the sections will pivot about the contactingpoint to shift the direction of pulling forces on the segments towardalignment with the bolt axis.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of acoupler and latch mechanism constructed in accordance with theinvention, shown before tightening with the latch section bridgesengaging the coupler segments.

FIG. 2 is a top plan view of the latch and coupler.

FIG. 3 is a detailed cross-sectional view taken along the line 3-3 ofFIG. 1 to show the coupler segment construction.

FIG. 4 is a fragmentary side elevational view showing the latchmechanism just prior to reaching the proper closing torque, with thelatch sections in contact and the pivot bridges lifting off thesegments.

FIG. 5 is a fragmentary side elevational view similar to FIG. 4 butshowing the contact position of the latch sections at the assembledposition with the pivot bridges lifted off the segments.

DESCRIPTION OF THE PREFERRED EMBODIMENT The assembly is generallyindicated at 11 and comprises a V band coupler generally indicated at 12and a latch mechanism generally indicated at 13. The coupler is byitself of conventional construction, having a pair of arcuate segments14 and 15 pivoted to opposite ends of a hinge 16. The cross-sectionalshape of each segment is shown in FIG. 3, comprising a web portion 17and diverging flanges 18 which serve to draw together complementaryflanges (not shown) of aligned ducts or other members to be secured.

Latch mechanism 13 comprises a pair of latch sections generallyindicated at 19 and 20 pivotally connected to segments 14 and 15respectively. Section 19 has a pair of side flanges 21 the lower ends ofwhich are connected to segment 14 by a pivot pin 22, a bridge 23connecting intermediate portions of these side flanges. This bridge isengageable with the flat upper edge 24 of segment 14 as seen in FIG. 1,but is swingable away from such contact 'to the positions shown in FIGS.4 and 5.

The outwardly facing edges 25 of flanges 21 are of concave shape toaccommodate the complementary surface of a spacer 26. The spacertransmits forces to latch section 19 from a nut 27 mounted on a bolt 28.This bolt passes through the flanges 21 of latch section 19 and its head29 is pivoted at 30 between the flanges 31 of latch section 20.

The latter section is shaped similarly to latch section 19 in that thelower ends of flanges 31 are pivoted at 32 to the upper end of couplersegment 15. Section 20 has a bridge 33, an intermediate portion thereofbeing engageable with the upper flat surface 34 of segment 15 when inthe position of FIG. 1. As in the case of bridge 23, bridge 33 can beswung away from contact with surface 34 to the positions shown in FIGS.4 and 5.

Bolt 28 is provided with a necked-down portion 35 (FIG. 2) which willrupture when excessive torque is placed on nut 27. Means are providedfor preventing complete separation of the ducting or'other clamped partswhen this occurs. A U-shaped cage 36 has its central portion disposedbetween nut 27 and spacer 26, and its legs extending along oppositesides of the latch mechanism. These legs have guide slots 37 whichareretained by enlarged portions 38 on pivot 30. Thus, upon rupture of thebolt the latch mechanism will open only until pivot 30 reaches the endsof slots 37, maintaining the coupler in a semi-closed position.

The latch pivot means is so arranged as to allow large installationtorques to be applied without overstressing coupler segments 14 and 15.This is done by changing the loading mode acting on the segments astorque is increased on nut 27, from a combined rotary and translatoryforce to a direct translatory force parallel to the bolt axis. Thisavoids overstressing the coupler segment ends and permits a lighterconstruction for any predetermined load requirements.

The means for accomplishing this comprises the facing pairs of straightedges 39 and 41 of latch sections 19 and 20 respectively, together withthe relative positions of bridges 23 and 33. The construction is suchthat during initial tightening of nut 27, as shown in FIG.

1, bridges 23 and 33 will be supported by surfaces 24 and 34respectively of the segments. As a result, the forces exerted by thelatch sections on the coupler segments will be in the directions ofarrows 42 and 43. These forces are the resultant of the tendency of thelatch sections to rotate about contacting bridges 23 and 33 and thedirect pull in the direction of the bolt axis. It will be observed thatthese forces are being transferred through relatively weak portions ofthe coupler segments.

Further tightening of nut 27 will cause the upper portions of edges 39and 41 to come into contact, as shown in FIG. 4. This will be achievedprior to reaching the proper closing torque. Continued tightening of nut27 will thus cause sections 19 and 20 to pivot about their contact point44 rather than tending to pivot at bridges 23 and 33. Since point 44 isabove the axis of bolt 28, the lower portions of sections 19 and 20 willbe drawn together in an axial direction. Bridges 23 and 33 will begin tobe lifted off surfaces 24 and 34 respectively, and the directions of theforces acting on segments 14 and will be as indicated by arrows 45 and46. That is, these forces will become more aligned with the axis of bolt28. Convex spacer 26 will slide on edges 25 of flanges 21 during thismovement to maintain the alignment of bolt 28.

As the proper closing torque is reached, straight edges 39 and 41 willcome into full contact with each other as shown in FIG. 5. Bridges 23and 33 will be lifted off surfaces 23 and 34 respectively and the forcesacting on segments 14 and 15 will be as shown by arrows 47 and 48, thatis, parallel to the axis of bolt 28. At this time, the forces will beacting on these segments through relatively strong portions thereof,thus protecting the segments against damage.

After fully bottoming against eachother straight edges 39 and 41, thelower portions of which are in alignment with the bolt axis, willfurther protect the segments by allowing no additional torque to betransferred thereto. Any overtorque on nut 27 will be taken up in thelatch itself, protecting the segments.

It should be observed that parts of the latch mechanism such as sections19 and could be fabricated as stampings, thus substantially reducing thecost of manufacture of the assembly.

I claim:

1. In combination, a latch mechanism for drawing two parts togethercomprising first and second latch sections, each section having a pairof flanges pivoted to one of said parts, each part having a pair offlanges joined by an outer web, each section being pivoted by a pivotpin passing through said section flanges adjacent said web, each sectionfurther having a bridge engageable with the top of said part and a pairof straight edges facing the edges of the other latch section, and boltand nut members interconnecting said latch sections, relative rotationof said members drawing the sections together and causing said bridgesto engage the tops of said parts, whereby combined rotary andtranslatory forces will be exerted by said sections on said parts whichwill cause said pivot pins to exert an outward force component on saidpart flanges, continued relative rotation of said members causing saidfacing pairs of edges to abut each other on the side of the bolt axisopposite said parts, whereby said bridges will be lifted from engagementwith said parts to reduce said outward force component and thedirections of forces on said parts will be shifted toward alignment withthe bolt axis.

2. The combination according to claim 1, the lower portions of saidedges being in alignment with said bolt axis, whereby full engagement ofsaid edges will prevent overtorquing forces from being transmitted tosaid parts.

3. In combination, a coupler having facing arcuate segments pivoted to ahinge at the bottom, each segment having a pair of flanges joined by anouter web, and a latch mechanism for drawing together the tops of saidsegments, said latch mechanism comprising two latch sections pivoted tosaid segments by pivot pins passing through said flanges adjacent saidweb, a bolt having a head pivoted to one section and passing through theother section, a nut on said bolt, means responsive to rotation of saidnut for drawing together said segments, bridges on said latch sectionsbetween said bolt and said pivot pins engageable with tops of saidsegments during initial tightening of the nut to create a combinedrotational and direct pulling force on the segments which will causesaid pivot pins to exert an outward force component on said segmentflanges, and facing edges on the segments so shaped that continuedtightening of the nut will cause the edges to contact each other abovethe bolt axis, whereby the sections will pivot about the contactingpoint to reduce said outward force component and shift the direction ofpulling forces on the segments toward alignment with the bolt axis.

4. The combination according to claim 3, said facing edges beingstraight whereby the edges will come into complete contact in responseto increased torquing of the nut, the lower portions of the facing edgesbeing in alignment with the bolt axis, thus preventing excessive forcefrom being placed on the segments.

5. The combination according to claim 4, said bolt having a necked-downportion subject to rupture upon overtorquing, and a cage interconnectingsaid latch sections to maintain them in a semi-closed position upon suchrupture.

6. In combination, a coupler having facing arcuate segments pivoted to ahinge at the bottom, and a latch mechanism for drawing together the topsof said segments, said latch mechanism comprising twolatch sectionspivoted to said segments, a bolt having a head pivoted to one sectionand passing through the other section, a nut on said bolt, meansresponsive to rotation of said nut for drawing together said segments,bridges on said latch sections engageable with tops of said segmentsduring initial tightening of the nut to create a combined rotational anddirect pulling force on the segments, and facing edges on the segmentsso shaped that continued tightening of the nut will cause the edges tocontact each other above the bolt axis, whereby the sections will pivotabout the contacting point to shift the direction of pulling forces onthe segment toward alignment with the bolt axis, said facing edges beingstraight whereby the edges will come into complete contact in responseto increased torquing of the nut, the lower portions of the facing edgesbeing in alignment with the bolt axis, thus preventing excessive forcefrom being placed on the segments, said pivotal bolt connection havingretaining portions engaging said cage, the cage being U-shaped with itscentral portion mounted on said bolt.

7. In combination, a pair of V band arcuate coupler segments pivoted toa hinge at their bottoms, flat upper surfaces on said arcuate segments,a latch mechanism comprising a pair of latch sections with side flanges,lower portions of said flanges being pivoted to the upper portions ofsaid segments, bridges on said latch sections disposed above said flatsegment surfaces, a bolt pivoted to one latch section and extendingthrough the other section, a nut on said bolt, convex spacer meansbetween said nut and other latch section, and facing straight edges onsaid latch sections, the relative proportions of the parts being suchthat upon initial nut torquing said bridges will engage said upper anyfurther forces on the segments.

1. In combination, a latch mechanism for drawing two parts togethercomprising first and second latch sections, each section having a pairof flanges pivoted to one of said parts, each part having a pair offlanges joined by an outer web, each section being pivoted by a pivotpin passing through said section flanges adjacent said web, each sectionfurther having a bridge engageable with the top of said part and a pairof straight edges facing the edges of the other latch section, and boltand nut members interconnecting said latch sections, relative rotationof said members drawing the sections together and causing said bridgesto engage the tops of said parts, whereby combined rotary andtranslatory forces will be exerted by said sections on said parts whichwill cause said pivot pins to exert an outward force component on saidpart flanges, continued relative rotation of said members causing saidfacing pairs of edges to abut each other on the side of the bolt axisopposite said parts, whereby said bridges will be lifted from engagementwith said parts to reduce said outward force component and thedirections of forces on said parts will be shifted toward alignment withthe bolt axis.
 2. The combination according to claim 1, the lowerportions of said edges being in alignment with said bolt axis, wherebyfull engagement of said edges will prevent overtorquing forces frombeing transmitted to said parts.
 3. In combination, a coupler havingfacing arcuate segments pivoted to a hinge at the bottom, each segmenthaving a pair of flanges joined by an outer web, and a latch mechanismfor drawing together the tops of said segments, said latch mechanismcomprising two latch sections pivoted to said segments by pivot pinspassing through said flanges adjacent said web, a bolt having a headpivoted to one section and passing through the other section, a nut onsaid bolt, means responsive to rotation of said nut for drawing togethersaid segments, bridges on said latch sections between said bolt and saidpivot pins engageable with tops of said segments during initialtightening of the nut to create a combined rotational and direct pullingforce on the segments which will cause said pivot pins to exert anoutward force component on said segment flanges, and facing edges on thesegments so shaped that continued tightening of the nut will cause theedges to contact each other above the bolt axis, whereby the sectionswill pivot about the contacting point to reduce said outward forcecomponent and shift the direction of pulling forces on the segmentstoward alignment with the bolt axis.
 4. The combination according toclaim 3, said facing edges being straight whereby the edges will comeinto complete contact in response to increased torquing of the nut, thelower portions of the facing edges being in alignment with the boltaxis, thus preventing excessive force from being placed on the segments.5. The combination according to claim 4, said bolt having a necked-downportion subject to rupture upon overtorquing, and a cage interconnectingsaid latch sections to maintain them in a semi-closed position upon suchrupture.
 6. In combination, a coupler having facing arcuate segmentspivoted to a hinge at the bottom, and a latch mechanism for drawingtogether the tops of said segments, said latch mechanism comprising twolatch sections pivoted to said segments, a bolt having a head pivoted toone section and passing through the other section, a nut on said bolt,means responsive to rotation of said nut for drawing together saidsegments, bridges on said latch sections engageable with tops of saidsegments during initial tightening of the nut to create a combinedrotational and direct pulling force on the segments, and facing edges onthe segments so shaped that continued tightening of the nut will causethe edges to contact each other above the bolt axis, whereby thesections will pivot about the contacting point to shift the direction ofpulling forces on the segment toward alignment with the bolt axis, saidfacing edges being straight whereby the edges will come into completecontact in response to increased torquing of the nut, the lower portionsof the facing edges being in alignment with the bolt axis, thuspreventing excessive force from being placed on the segments, saidpivotal bolt connection having retaining portions engaging said cage,the cage being U-shaped with its central portion mounted on said bolt.7. In combination, a pair of ''''V'''' band arcuate coupler segmentspivoted to a hinge at their bottoms, flat upper surfaces on said arcuatesegments, a latch mechanism comprising a pair of latch sections withside flanges, lower portions of said flanges being pivoted to the upperportions of said segments, bridges on said latch sections disposed abovesaid flat segment surfaces, a bolt pivoted to one latch section andextending through the other section, a nut on said bolt, convex spacermeans between said nut and other latch section, and facing straightedges on said latch sections, the relative proportions of the partsbeing such that upon initial nut torquing said bridges will engage saidupper segment surfaces to provide a combined rotational and directpulling force on said segments, continued torquing causing the upperportions of said facing edges to contact above the bolt axis whereby thelatch sections will pivot about the contact points and bring the forcesacting on the segment closer to alignment with the bolt axis while saidbridges lift from said segment surfaces, the lower portions of saidfacing edges being in alignment with the bolt axis whereby fullengagement of the facing edges will prevent overtorquing from exertingany further forces on the segments.